论文部分内容阅读
为分析高速电弧喷涂工艺制备Zn-Al-Mg-RE防腐涂层的氧化行为,通过XRD、SEM和EDS试验探究了喷涂工艺对该涂层氧化物的组成、含量及其形态的影响规律,并测试了涂层的中性盐雾腐蚀性能。结果发现:该涂层具有典型的层状结构特征,在相互叠加的扁平颗粒之间有很薄的氧化物膜,同时在扁平颗粒的内部也非均匀地分布着富氧化物区,XRD显示这些氧化物主要为ZnO2和尖晶石结构的ZnAl2O4与MgAl2O4等。分析认为:喷涂时液态金属熔滴在高速气流剪切力作用和反应热梯度作用下,加剧了Zn-Al-Mg-RE熔滴的氧化,这些交错分布的氧化物对合金相产生了较好的屏蔽效果,从而提高了涂层的耐蚀性能。
In order to analyze the oxidation behavior of Zn-Al-Mg-RE anticorrosive coating prepared by high-speed arc spraying process, the influence of spraying process on the composition, content and morphology of Zn-Al-Mg-RE anticorrosive coating was investigated by XRD, SEM and EDS The coating was tested for neutral salt spray corrosion. As a result, it was found that the coating has a typical lamellar structure characterized by a thin oxide film between the flat particles superimposed on each other and an oxide-rich region also unevenly distributed inside the flat particles, which are shown by XRD The main oxides are ZnAl 2 O 4 and spinel ZnAl 2 O 4 and MgAl 2 O 4. The results show that the droplets of liquid Zn-Al-Mg-RE are accelerated by the high-speed airflow shear force and the reaction thermal gradient during the spraying process. These staggered oxides produce a better effect on the alloy phase The shielding effect, thereby enhancing the corrosion resistance of the coating.